There has been proposed an image forming apparatus having a function of supplying electric charge to a conveying belt to electrically cling a sheet to the conveying belt in order to stably convey the sheet. Specifically, the image forming apparatus includes a charge supply unit and a conductive ground roller, and is configured to apply a bias to the charge supply unit to supply electric charge to the conveying belt so that the sheet clings to the conveying belt at a position where the conveying belt and the conductive ground roller face each other. Further, the image forming apparatus continuously applies a constant bias to the charge supply unit over an entire period of time when a conveying portion of the belt where the entirety of the sheet is disposed is present at the facing position.